IMD updated forecast: 2026 monsoon likely below normal at 90% of LPA as El Niño develops
In its second-stage forecast on 29 May 2026, IMD said the 2026 southwest monsoon (June–September) rainfall is likely to be 90% of the Long Period Average (±4%), with an 84% probability of below-normal or less rainfall.
Summary
The India Meteorological Department issued its updated (second-stage) long range forecast for the 2026 southwest monsoon on 29 May 2026. Country-wide June–September rainfall is likely to be 90% of the Long Period Average with a model error of ±4%; the LPA, based on 1971–2020, is 87 cm. There is an 84% probability of below-normal or less rainfall. Neutral ENSO conditions are moving towards El Niño, which is likely to develop during the season, while neutral Indian Ocean Dipole conditions are expected to continue. The first-stage forecast was issued on 13 April 2026.
Key facts
- Forecast
- Updated (2nd stage) LRF, 29 May 2026
- Seasonal rainfall
- 90% of LPA (±4%)
- LPA
- 87 cm (1971–2020 base)
- Probability
- 84% for below normal or less
- ENSO
- El Niño likely to develop during the monsoon
- IOD
- Neutral, likely to continue
- First-stage forecast
- 13 April 2026
- Model
- Multi-Model Ensemble incl. Monsoon Mission CFS
Practice MCQs 4 questions
As per IMD's updated forecast of 29 May 2026, the 2026 southwest monsoon seasonal rainfall over India is likely to be what percentage of the Long Period Average?
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Correct answer: B — 90%
IMD forecast seasonal rainfall at 90% of the LPA with a model error of ±4%.
The Long Period Average (LPA) of India's southwest monsoon seasonal rainfall, based on 1971–2020 data, is:
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Correct answer: B — 87 cm
IMD states that the LPA of seasonal rainfall over the country based on 1971–2020 data is 87 cm.
Consider the following statements about IMD's updated monsoon forecast (May 2026): 1. El Niño conditions are likely to develop during the monsoon season. 2. A positive Indian Ocean Dipole is expected to develop during the season. Which of the statements given above is/are correct?
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Correct answer: A — 1 only
IMD said El Niño is likely to develop during the season, while neutral IOD conditions are likely to continue.
IMD's 2026 updated forecast gave what probability for below-normal or less rainfall for the country as a whole?
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Correct answer: C — 84%
The five-category probability forecast suggests an 84% probability of below normal or less rainfall.